JP7403320B2 - Substrate processing equipment - Google Patents

Description

The disclosed embodiments relate to a substrate processing apparatus.

Conventionally, when a film formed on a substrate such as a semiconductor wafer (hereinafter also referred to as a wafer) contains two types of materials (for example, a wiring material and a diffusion prevention film), one material is selectively used. An etching technique is known (see Patent Document 1).

Japanese Patent Application Publication No. 2008-285508

The present disclosure provides a technique that can suppress occurrence of a bumping reaction in a mixing part when etching processing using a mixed liquid is completed.

A substrate processing apparatus according to one aspect of the present disclosure includes a temperature raising section, a mixing section, and a discharge section. The temperature raising section raises the temperature of sulfuric acid. The mixing section mixes heated sulfuric acid and a liquid containing water to generate a mixed liquid. The discharge section discharges the mixed liquid onto the substrate within the substrate processing section. Further, the mixing section includes a merging section where a sulfuric acid supply line through which the heated sulfuric acid flows and a liquid supply line through which the liquid flows, and a reaction between the heated sulfuric acid and the liquid at the merging section. It has a reaction suppression mechanism.

According to the present disclosure, it is possible to suppress the bumping reaction from occurring in the mixing portion when the etching process using the mixed liquid is completed.

FIG. 1 is a schematic diagram showing a schematic configuration of a substrate processing system according to an embodiment. FIG. 2 is a schematic diagram showing a specific example of the configuration of the processing unit. FIG. 3 is a diagram showing an outline of the etching process in the embodiment. FIG. 4 is a diagram showing the configuration of the mixed liquid supply section according to the embodiment. FIG. 5 is a diagram showing the configuration of the reaction suppression mechanism according to the embodiment. FIG. 6 is a timing chart showing a specific example of the behavior pattern of each part in the etching process according to the embodiment. FIG. 7 is a diagram showing reaction stop times in Examples and Reference Examples. FIG. 8 is a diagram showing the configuration of a reaction suppression mechanism according to Modification 1 of the embodiment. FIG. 9 is a diagram showing the reaction stop time of Modification 1 and Reference Example. FIG. 10 is a diagram showing the configuration of a reaction suppression mechanism according to modification 2 of the embodiment. FIG. 11 is a timing chart showing a specific example of the behavior pattern of each part in the etching process according to Modification 2 of the embodiment. FIG. 12 is a diagram for explaining the operation of the reaction suppression mechanism according to Modification 2 of the embodiment. FIG. 13 is a diagram showing the configuration of a reaction suppression mechanism according to modification 3 of the embodiment. FIG. 14 is a timing chart showing a specific example of the behavior pattern of each part in the etching process according to Modification 3 of the embodiment. FIG. 15 is a diagram showing the configuration of a reaction suppression mechanism according to modification 4 of the embodiment. FIG. 16 is a timing chart showing a specific example of the behavior pattern of each part in the etching process according to Modification 4 of the embodiment. FIG. 17 is a diagram showing the configuration of a reaction suppression mechanism according to modification 5 of the embodiment. FIG. 18 is a diagram showing the configuration of a reaction suppression mechanism according to modification 6 of the embodiment.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a substrate processing apparatus disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present disclosure is not limited to the embodiments described below. Furthermore, it should be noted that the drawings are schematic, and the dimensional relationship of each element, the ratio of each element, etc. may differ from reality. Furthermore, drawings may include portions with different dimensional relationships and ratios.

Conventionally, when a film formed on a substrate such as a semiconductor wafer (hereinafter also referred to as a wafer) contains two types of materials (for example, a wiring material and a diffusion prevention film), one material is selectively used. Etching techniques are known. In order to etch one of the materials with high selectivity, a mixture of a plurality of types of heated sulfuric acid or the like may be used as an etching solution.

On the other hand, when a liquid mixture is generated by mixing chemical liquids such as sulfuric acid in a pipe, the chemical liquids react in the mixing part, and the temperature rises to the boiling point, causing bumping of the liquid mixture. Therefore, when stopping the discharge of the mixed liquid to end the etching process, the chemical liquid in the piping vibrates due to bumping, so one of the chemical liquids (for example, sulfuric acid) should not be used until the bumping reaction in the mixing section subsides. I had to keep it flowing.

In other words, in the conventional technology, even after the etching process using the mixed liquid M is completed, it is necessary to discharge a chemical such as sulfuric acid until the bumping subsides, which lengthens the overall processing time and reduces consumption of the chemical. There was a risk that the amount would increase.

Therefore, there is a need for a technique that can overcome the above-mentioned problems and suppress the occurrence of bumping reactions in the mixing part when etching processing using a mixed liquid is completed.

<Summary of substrate processing system>
First, a schematic configuration of a substrate processing system 1 according to an embodiment will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of a substrate processing system 1 according to an embodiment. Note that the substrate processing system 1 is an example of a substrate processing apparatus. In the following, in order to clarify the positional relationship, an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other are defined, and the positive direction of the Z-axis is defined as a vertically upward direction.

As shown in FIG. 1, the substrate processing system 1 includes a loading/unloading station 2 and a processing station 3. The loading/unloading station 2 and the processing station 3 are provided adjacent to each other.

The loading/unloading station 2 includes a carrier mounting section 11 and a transport section 12. A plurality of carriers C that horizontally accommodate a plurality of substrates, in the embodiment semiconductor wafers W (hereinafter referred to as wafers W), are placed on the carrier mounting section 11 .

The transport section 12 is provided adjacent to the carrier mounting section 11 and includes a substrate transport device 13 and a delivery section 14 inside. The substrate transfer device 13 includes a wafer holding mechanism that holds the wafer W. Further, the substrate transfer device 13 is capable of horizontal and vertical movement and rotation about a vertical axis, and uses a wafer holding mechanism to transfer the wafer W between the carrier C and the transfer section 14. conduct.

The processing station 3 is provided adjacent to the transport section 12 . The processing station 3 includes a transport section 15 and a plurality of processing units 16. The plurality of processing units 16 are arranged side by side on both sides of the transport section 15 .

The transport unit 15 includes a substrate transport device 17 therein. The substrate transfer device 17 includes a wafer holding mechanism that holds the wafer W. Further, the substrate transfer device 17 is capable of horizontal and vertical movement and rotation about a vertical axis, and is capable of transferring wafers W between the transfer section 14 and the processing unit 16 using a wafer holding mechanism. I do.

The processing unit 16 performs predetermined substrate processing on the wafer W transported by the substrate transport device 17 .

The substrate processing system 1 also includes a control device 4 . The control device 4 is, for example, a computer, and includes a control section 18 and a storage section 19. The storage unit 19 stores programs that control various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing a program stored in the storage unit 19 .

Note that this program may be one that has been recorded on a computer-readable storage medium, and may be installed in the storage unit 19 of the control device 4 from the storage medium. Examples of computer-readable storage media include hard disks (HD), flexible disks (FD), compact disks (CD), magnetic optical disks (MO), and memory cards.

In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 of the loading/unloading station 2 takes out the wafer W from the carrier C placed on the carrier mounting section 11, and receives the taken out wafer W. Place it on Watabe 14. The wafer W placed on the transfer section 14 is taken out from the transfer section 14 by the substrate transport device 17 of the processing station 3 and carried into the processing unit 16.

The wafer W carried into the processing unit 16 is processed by the processing unit 16, and then carried out from the processing unit 16 by the substrate transport device 17 and placed on the transfer section 14. The processed wafer W placed on the transfer section 14 is then returned to the carrier C of the carrier mounting section 11 by the substrate transfer device 13.

<Processing unit configuration>
Next, the configuration of the processing unit 16 will be explained with reference to FIG. 2. FIG. 2 is a schematic diagram showing a specific example of the configuration of the processing unit 16. As shown in FIG. 2, the processing unit 16 includes a chamber 20, a substrate processing section 30, a liquid supply section 40, and a recovery cup 50.

The chamber 20 accommodates a substrate processing section 30, a liquid supply section 40, and a collection cup 50. An FFU (Fan Filter Unit) 21 is provided on the ceiling of the chamber 20 . FFU 21 forms a downflow within chamber 20 .

The substrate processing section 30 includes a holding section 31, a support section 32, and a driving section 33, and performs liquid processing on the mounted wafer W. The holding section 31 holds the wafer W horizontally. The support portion 32 is a member extending in the vertical direction, has a base end rotatably supported by a drive portion 33, and a distal end portion that supports the holding portion 31 horizontally. The drive section 33 rotates the support section 32 around a vertical axis.

The substrate processing section 30 rotates the holding section 31 supported by the supporting section 32 by rotating the supporting section 32 using the driving section 33, thereby rotating the wafer W held on the holding section 31. .

A holding member 311 that holds the wafer W from the side is provided on the upper surface of the holding section 31 included in the substrate processing section 30. The wafer W is held horizontally by the holding member 311 while being slightly spaced from the upper surface of the holding section 31 . Note that the wafer W is held by the holding unit 31 with the surface on which substrate processing is performed facing upward.

The liquid supply unit 40 supplies processing fluid to the wafer W. The liquid supply unit 40 includes a plurality of nozzles 41a and 41b (two in this case), an arm 42 that horizontally supports the nozzles 41a and 41b, and a turning and lifting mechanism 43 that turns and raises and lowers the arm 42.

The nozzle 41a is an example of a discharge section, and is connected to the mixed liquid supply section 60 via a valve 44a and a flow rate regulator 45a. Details of the mixed liquid supply section 60 will be described later.

Nozzle 41b is connected to DIW source 46b via valve 44b and flow regulator 45b. DIW (DeIonized Water) is used, for example, for rinsing. Note that the processing liquid used for the rinsing process is not limited to DIW.

The mixed liquid M (see FIG. 3) supplied from the mixed liquid supply section 60 is discharged from the nozzle 41a. Details of this mixed liquid M will be described later. DIW supplied from the DIW supply source 46b is discharged from the nozzle 41b.

The collection cup 50 is arranged to surround the holding part 31 and collects the processing liquid scattered from the wafer W by the rotation of the holding part 31. A drain port 51 is formed at the bottom of the recovery cup 50, and the processing liquid collected by the recovery cup 50 is discharged to the outside of the processing unit 16 from the drain port 51. Furthermore, an exhaust port 52 is formed at the bottom of the collection cup 50 to discharge the gas supplied from the FFU 21 to the outside of the processing unit 16 .

Note that although the processing unit 16 of the embodiment has been shown as an example in which two nozzles are provided, the number of nozzles provided in the processing unit 16 is not limited to two. For example, an IPA supply source that supplies IPA (IsoPropyl Alcohol) and a third nozzle connected to the IPA supply source may be provided, and IPA may be discharged from the third nozzle.

<Details of cleaning process>
Next, details of the etching process of the wafer W in the processing unit 16 will be explained with reference to FIG. FIG. 3 is a diagram showing an outline of the etching process in the embodiment. It is assumed that the film formed on the surface of the wafer W subjected to such etching processing contains tungsten (W) and titanium nitride (TiN), which are different materials.

First, the wafer W is carried into the chamber 20 of the processing unit 16 by the substrate transfer device 17 . The wafer W is held by the holding member 311 of the substrate processing section 30 with the surface to be processed facing upward. Thereafter, the holding member 311 is rotated together with the wafer W at a predetermined rotational speed by the drive unit 33.

Next, in the processing unit 16, as shown in FIG. 3(a), an etching process is performed using the mixed liquid M. In this etching process, the nozzle 41a of the liquid supply section 40 moves above the center of the wafer W.

Thereafter, by opening the valve 44a for a predetermined time, the liquid mixture M containing concentrated sulfuric acid is supplied to the surface of the wafer W.

Here, in the embodiment, the mixed liquid M heated to a predetermined temperature or higher is supplied to the wafer W. As a result, reactions of the following formulas (1) and (2) occur within the mixed liquid M.
2H ₂ SO ₄ → H ₃ SO ₄ ⁺ + HSO ₄ ^-... (1)
H ₃ SO ₄ ⁺ → H ⁺ + H ₂ SO ₄ ...(2)

Then, H ⁺ generated in the above reaction selectively reacts with titanium nitride out of tungsten and titanium nitride contained in the film formed on the surface of the wafer W, as shown in equation (3) below.
TiN + 4H ⁺ → Ti ³⁺ + NH ₄ ⁺ ...(3)

Here, since Ti ³⁺ generated in the reaction of formula (3) is dissolved in the mixture M, the mixture M selectively etches titanium nitride based on the reactions of formulas (1) to (3) above. can do. Therefore, according to the embodiment, of the tungsten and titanium nitride contained in the film formed on the surface of the wafer W, titanium nitride can be etched with high selectivity.

Further, in the embodiment, it is preferable to perform the etching process using a mixed solution M obtained by adding pure water to concentrated sulfuric acid. As a result, reactions of the following equations (4) and (5) occur in the mixed liquid M in addition to the reactions of the above equations (1) and (2).
H ₂ O + H ₂ SO ₄ → H ₃ O ⁺ + HSO ₄ ^- (4)
H ₃ O ⁺ → H ⁺ + H ₂ O...(5)

Through the reactions of formulas (4) and (5), more H ⁺ is supplied into the mixed liquid M. Thereby, in the embodiment, since the reaction of the above formula (3) is promoted, the mixed liquid M can further selectively etch titanium nitride.

Returning to the explanation of FIG. 3. Next, in the processing unit 16, as shown in FIG. 3(b), sulfuric acid is discharged from the nozzle 41a. In this process, when stopping the discharge of the mixed liquid M from the nozzle 41a, if the supply of sulfuric acid and the supply of DIW are stopped at the same time, the sulfuric acid and DIW will bump in the piping, resulting in the boiling of the liquid mixture M at the nozzle 41a. This is done because it is difficult to properly drain the liquid.

Specifically, only sulfuric acid is discharged from the nozzle 41a until the bumping reaction between the sulfuric acid and DIW in the mixing part 140 (see FIG. 4) subsides, and then the nozzle 41a is drained. The liquid drain process can be carried out without any problems.

In addition, in the sulfuric acid discharge process shown in FIG. 3(b), since the sulfuric acid does not react with DIW in the mixing section 140, the temperature of the sulfuric acid is lower than that of the mixed liquid M, and the equations (4) and (5) above are No reaction occurs. That is, the sulfuric acid discharge process hardly contributes to the etching process of the wafer W. Note that details of the sulfuric acid discharge process will be described later.

Next, in the processing unit 16, as shown in FIG. 3(c), a rinsing process using DIW is performed. In this rinsing process, the nozzle 41b of the liquid supply unit 40 moves above the center of the wafer W, and the valve 44b is opened for a predetermined period of time, so that DIW at room temperature, which is a rinsing liquid, is supplied to the surface of the wafer W. Ru.

By this rinsing process, the mixed liquid M remaining on the wafer W and residues of etched titanium nitride can be removed. Note that the temperature of DIW in the rinsing process may be at room temperature or higher than room temperature.

Subsequently, in the processing unit 16, a drying process is performed to dry the wafer W. In this drying process, for example, the drive unit 33 rotates the holding member 311 at high speed to shake off the DIW on the wafer W held by the holding member 311. Note that instead of shaking off the DIW, the DIW may be replaced with IPA, and then the IPA may be shaken off to dry the wafer W.

Thereafter, in the processing unit 16, an unloading process is performed. In the unloading process, after the rotation of the wafer W is stopped, the wafer W is unloaded from the processing unit 16 by the substrate transport device 17 . When this unloading process is completed, a series of etching processes for one wafer W is completed.

<Configuration of mixed liquid supply section>
Next, the configuration of the mixed liquid supply section 60 included in the substrate processing system 1 will be described with reference to FIG. 4. FIG. 4 is a diagram showing the configuration of the mixed liquid supply section 60 according to the embodiment. Note that each part of the mixed liquid supply section 60 shown below can be controlled by the control section 18.

As shown in FIG. 4, the mixed liquid supply section 60 according to the embodiment includes a sulfuric acid supply section 100, a pure water supply section 120, and a mixing section 140.

The sulfuric acid supply section 100 supplies sulfuric acid to the mixing section 140. Such sulfuric acid is, for example, concentrated sulfuric acid. The sulfuric acid supply unit 100 includes a sulfuric acid supply source 101a, a valve 101b, a flow rate regulator 101c, a tank 102, a circulation line 103, and a sulfuric acid supply line 110.

Sulfuric acid supply source 101a is connected to tank 102 via valve 101b and flow regulator 101c. Thereby, the sulfuric acid supply source 101a can supply sulfuric acid to the tank 102 via the valve 101b and the flow rate regulator 101c, and can store the sulfuric acid in the tank 102.

The circulation line 103 is a circulation line that exits the tank 102 and returns to the tank 102. The circulation line 103 is provided with a pump 104, a filter 105, a flow rate regulator 106, a heater 107, a thermocouple 108, and a switching unit 109 in order from the upstream side with respect to the tank 102. The heater 107 is an example of a temperature increasing section.

Pump 104 creates a circulating flow of sulfuric acid exiting tank 102, passing through circulation line 103, and returning to tank 102. Filter 105 removes contaminants such as particles contained in the sulfuric acid circulating within circulation line 103 . Flow regulator 106 regulates the flow rate of the circulating flow of sulfuric acid through circulation line 103 .

The heater 107 heats the sulfuric acid circulating within the circulation line 103. Thermocouple 108 measures the temperature of sulfuric acid circulating within circulation line 103. Therefore, the control unit 18 can control the temperature of the sulfuric acid circulating in the circulation line 103 by using the heater 107 and the thermocouple 108.

The switching unit 109 is connected to the mixing unit 140 of the mixed liquid supply unit 60 via the sulfuric acid supply line 110, and can switch the direction of the sulfuric acid circulating in the circulation line 103 to the tank 102 or the mixing unit 140.

The sulfuric acid supply line 110 is provided with a flow meter 111, an electric needle valve 112, a valve 113, and a branch part 114 in order from the upstream side with the switching part 109 as a reference.

Flow meter 111 measures the flow rate of sulfuric acid flowing through sulfuric acid supply line 110. Needle valve 112 regulates the flow rate of sulfuric acid flowing through sulfuric acid supply line 110 . Branch portion 114 is connected to drain portion DR via valve 115.

The control unit 18 can supply sulfuric acid to the mixing unit 140 at a highly accurate flow rate by feedback-controlling the needle valve 112 using the value measured by the flow meter 111.

Further, the tank 102 is provided with a pure water supply source 116a, a valve 116b, a flow rate regulator 116c, and a valve 116d. Tank 102 is connected to drain section DR via valve 116d, and pure water supply source 116a is connected between tank 102 and valve 116d via valve 116b and flow regulator 116c.

Accordingly, when replacing the sulfuric acid in the tank 102, the control unit 18 controls the valve 116b, the flow rate regulator 116c, and the valve 116d to dilute the concentrated sulfuric acid in the tank 102 to a predetermined concentration. It can be discharged to the drain part DR.

The pure water supply section 120 supplies DIW to the mixing section 140. Such DIW is an example of pure water and an example of a liquid containing water. The pure water supply unit 120 includes a pure water supply source 121a, a valve 121b, a flow regulator 121c, a tank 122, and a pure water supply line 123. The pure water supply line 123 is an example of a liquid supply line.

Pure water supply source 121a is connected to tank 122 via valve 121b and flow rate regulator 121c. Thereby, the pure water supply source 121a can supply pure water to the tank 122 via the valve 121b and the flow rate regulator 121c, and can store the pure water in the tank 122.

The pure water supply line 123 is provided with a valve 124, a flow meter 125, an electric needle valve 126, a valve 127, and a branch part 128 in order from the upstream side with respect to the tank 122.

The flow meter 125 measures the flow rate of pure water flowing through the pure water supply line 123. The needle valve 126 adjusts the flow rate of pure water flowing through the pure water supply line 123. Branch portion 128 is connected to drain portion DR via valve 129.

The control unit 18 can supply pure water to the mixing unit 140 at a highly accurate flow rate by feedback-controlling the needle valve 126 using the value measured by the flow meter 125.

Further, the tank 122 is connected to the drain portion DR via a valve 130. Thereby, when exchanging the pure water in the tank 122, the control unit 18 can control the valve 130 to discharge the pure water in the tank 122 to the drain unit DR.

The mixing unit 140 mixes sulfuric acid supplied from the sulfuric acid supply unit 100 and pure water supplied from the pure water supply unit 120 to generate a mixed liquid M (see FIG. 3). In the embodiment, the mixing section 140 is provided at a location where the sulfuric acid supply line 110 and the pure water supply line 123 join.

The mixing section 140 is connected to the processing unit 16 via a mixed liquid supply line 160. Further, the mixed liquid supply line 160 is provided with the above-mentioned valve 44a and flow rate regulator 45a. Thereby, the liquid mixture supply section 60 can supply the liquid mixture M having the mixing ratio set by the user to the processing unit 16.

Further, as described above, the sulfuric acid supply section 100 is provided with the heater 107, and in the mixing section 140, the temperature of the mixed liquid M increases as the sulfuric acid and pure water react. Thereby, the mixed liquid supply unit 60 of the embodiment can raise the temperature of the mixed liquid M to a desired temperature and supply it to the processing unit 16.

For example, the mixed liquid supply unit 60 raises the temperature of concentrated sulfuric acid to about 120°C using the heater 107 of the sulfuric acid supply unit 100, thereby raising the temperature of the mixed liquid M in the mixing unit 140 to about 150°C. Can be done.

Further, although not shown in FIG. 4, a separate valve or the like may be provided in the circulation line 103 or the like.

Here, in the embodiment, the mixing section 140 has a reaction suppression mechanism that suppresses the reaction between sulfuric acid and DIW. Thereby, when finishing the etching process of the wafer W with the liquid mixture M, it is possible to suppress the occurrence of a bumping reaction in the mixing part 140.

Therefore, according to the embodiment, it is possible to shorten the time for the sulfuric acid discharge process shown in FIG. can be reduced.

<Details of reaction inhibition mechanism>
Next, details of the reaction suppression mechanism provided in the mixing section 140 will be explained with reference to FIGS. 5 to 7. FIG. 5 is a diagram showing the configuration of the reaction suppression mechanism according to the embodiment.

As shown in FIG. 5, the mixing section 140 according to the embodiment includes a merging section 141 and a pipe buffer section 142. The confluence part 141 is a part where the sulfuric acid supply line 110 through which heated sulfuric acid flows and the pure water supply line 123 through which DIW flows merge.

Note that in the present disclosure, the merging section 141 is not limited to the area where the sulfuric acid supply line 110 and the pure water supply line 123 merge, but also includes the vicinity of such a merging area. The pipe buffer section 142 is a U-shaped section provided near the confluence section 141 in the pure water supply line 123.

In the embodiment shown in FIG. 5, the reaction between sulfuric acid and DIW in the confluence section 141 can be suppressed by the pipe buffer section 142. That is, the reaction suppression mechanism according to the embodiment is configured with the piping buffer section 142 provided in the pure water supply line 123.

The specific configuration will be explained below. In embodiments, the sulfuric acid supply line 110 and the pure water supply line 123 are connected upwardly to the confluence section 141 to flow the sulfuric acid and DIW upwardly to the confluence section 141 . Further, the mixed liquid supply line 160 allows the mixed liquid M (see FIG. 3) to flow upward from the confluence section 141.

The pipe buffer section 142 provided near the merging section 141 includes, in order from the upstream side, an ascending section 142a, a horizontal section 142b, and a descending section 142c.

The rising portion 142a is a portion connected to an upward portion of the pure water supply line 123 and provided at a higher position than the merging portion 141. The horizontal portion 142b is connected to the rising portion 142a and is a portion that allows DIW to flow approximately horizontally. The descending portion 142c is connected to the horizontal portion 142b and is a portion that allows DIW to flow downward.

Further, the descending portion 142c is connected to a horizontal portion 123a, which is a portion of the pure water supply line 123 through which DIW flows approximately horizontally. This horizontal portion 123a is connected to the merging portion 141.

That is, the DIW flowing upward in the pure water supply line 123 once changes its flow downward in the piping buffer section 142, and finally reaches the confluence section 141 in a substantially horizontal direction.

FIG. 6 is a timing chart showing a specific example of the behavior pattern of each part in the etching process according to the embodiment. First, the control unit 18 executes the mixed liquid discharge process shown in FIG. 3(a).

Specifically, the control unit 18 starts supplying sulfuric acid from the sulfuric acid supply line 110 to the mixing unit 140 at time T1 (sulfuric acid supply line: ON), and also starts supplying DIW from the pure water supply line 123 to the mixing unit 140. (Pure water supply line: ON).

As a result, the mixed liquid M is generated in the mixing unit 140, so that the control unit 18 can discharge the mixed liquid M through the nozzle 41a (see FIG. 4). Then, the control unit 18 continues the mixed liquid discharge process until a predetermined time T2.

Next, the control unit 18 executes the sulfuric acid discharge process shown in FIG. 3(b). Specifically, the control unit 18 stops the supply of DIW from the pure water supply line 123 to the mixing unit 140 at time T2 (pure water supply line: OFF).

As a result, the flow of DIW near the confluence section 141 is stopped, so that sulfuric acid flows back from the confluence section 141 to the pure water supply line 123, and the sulfuric acid and DIW react in the deionized water supply line 123. As a result, a bumping reaction occurs in the pure water supply line 123 near the confluence section 141 after time T2.

Therefore, the control unit 18 carries out the sulfuric acid discharge process until the time T3 when the bumping reaction subsides. Finally, the control unit 18 stops the supply of sulfuric acid from the sulfuric acid supply line 110 to the mixing unit 140 at time T3 (sulfuric acid supply line: OFF), opens the valve 115 (see FIG. 4), and opens the nozzle. The sulfuric acid remaining in 41a is drained. This completes the sulfuric acid discharge process according to the embodiment.

Here, in the embodiment, since the mixing section 140 has the pipe buffer section 142, bubbles generated by the bumping reaction are stored in the descending section 142c after time T2. In the embodiment, the bubbles stored in the descending portion 142c can suppress the backflow of sulfuric acid further upstream.

That is, in the embodiment, by including the pipe buffer section 142 in the mixing section 140, it is possible to suppress sulfuric acid from flowing back into the pure water supply line 123 when the etching process is finished. Therefore, according to the embodiment, it is possible to suppress the bumping reaction from occurring in the mixing section 140 when the etching process using the mixed liquid M is completed.

FIG. 7 is a diagram showing reaction stop times in Examples and Reference Examples. The embodiment shown in FIG. 7 is a case where the pipe buffer section 142 is provided in the mixing section 140, and the reference example is a case where the pipe buffer section 142 is not provided in the mixing section 140.

As shown in FIG. 7, in the embodiment, by providing the pipe buffer section 142 in the mixing section 140, the stop time of the bumping reaction can be shortened.

Further, in the embodiment, the top of the pipe buffer section 142 (the horizontal section 142b in the example of FIG. 5) is preferably higher than the confluence section 141. This makes it possible to prevent sulfuric acid, which has a higher specific gravity than DIW, from flowing backward from the confluence section 141 to the top (horizontal section 142b) of the pipe buffer section 142.

Therefore, according to the embodiment, it is possible to further suppress the bumping reaction from occurring in the mixing section 140 when the etching process using the mixed liquid M is completed.

Further, in the embodiment, it is preferable that the top of the piping buffer section 142 (the horizontal section 142b in the example of FIG. 5) is higher than the merging section 141 by at least the diameter D _B of the pure water supply line 123 at the merging section 141 . That is, when the height of the horizontal portion 142b with respect to the merging portion 141 is H, it is preferable that H≧D _B ×1.

As a result, the top of the pipe buffer section 142 (horizontal section 142b) can be reliably provided at a higher position than the merging section 141, which further suppresses sulfuric acid from flowing back to the top of the pipe buffer section 142. Can be done.

Further, in the embodiment, the piping buffer section 142 is preferably spaced apart from the mixed liquid supply line 160 by a distance greater than or equal to the diameter D of the mixed liquid supply line 160 at the confluence section 141 . That is, when the distance between the piping buffer section 142 and the mixed liquid supply line 160 is L1, it is preferable that L1≧D×1.

Thereby, it is possible to prevent the piping buffer section 142 and the mixed liquid supply line 160 from being arranged so as to overlap each other.

Note that the distance L1 between the piping buffer section 142 and the mixed liquid supply line 160 is preferably as short as possible (for example, L1≦D×5). As a result, the length of the sulfuric acid flowing back from the confluence section 141 (that is, the length of the horizontal section 123a) can be shortened, so that the occurrence of a bumping reaction in the mixing section 140 can be further suppressed.

In the embodiment, the angle between the sulfuric acid supply line 110 and the pure water supply line 123 at the confluence section 141 is not particularly limited, and may be any angle as long as the height H of the horizontal section 142b with respect to the confluence section 141 satisfies a specified dimension.

Further, in the embodiment, the diameter D of the mixed liquid supply line 160 is not particularly limited, and can be appropriately set according to the discharge flow rate of the mixed liquid M necessary for etching the wafer W.

Furthermore, in the embodiment, the diameter _DA of the sulfuric acid supply line 110 at the confluence section 141 and the diameter D _B of the pure water supply line 123 at the confluence section 141 are not particularly limited. In the embodiment, the diameter D _A and the diameter D _B can be appropriately set according to the discharge flow rates of sulfuric acid and DIW necessary for etching the wafer W.

For example, when the mixing ratio of sulfuric acid and DIW is 2:1, D _A :D _B may be 4 mm:2 mm. Of course, it is not limited to the mixing ratio of sulfuric acid and DIW, and it is also possible to set D _A = D _B.

<Various variations>
Next, various modifications of the reaction suppression mechanism according to the embodiment will be described with reference to FIGS. 8 to 18. FIG. 8 is a diagram showing the configuration of a reaction suppression mechanism according to Modification 1 of the embodiment.

As shown in FIG. 8, the mixing section 140 according to the first modification includes a merging section 141 and an orifice 143. The orifice 143 is another example of a reaction suppression mechanism, and is provided near the confluence section 141 in the pure water supply line 123.

In this modification example 1, since the mixing section 140 includes the orifice 143, it is possible to suppress sulfuric acid from flowing back into the pure water supply line 123 when the etching process is finished. Therefore, according to the first modification, it is possible to suppress the bumping reaction from occurring in the mixing section 140 when the etching process using the mixed liquid M is completed.

FIG. 9 is a diagram showing the reaction stop time of Modification 1 and Reference Example. The embodiment shown in FIG. 9 is a case where the mixing section 140 is provided with an orifice 143, and the reference example is a case where the mixing section 140 is not provided with an orifice 143.

As shown in FIG. 9, in Modification 1, by providing an orifice 143 in the mixing section 140, the stop time of the bumping reaction can be shortened.

Further, in the first modification, the inner diameter D _O of the orifice 143 is preferably 1/5 to 1/2 of the diameter D _B of the pure water supply line 123 in the confluence section 141.

If the inner diameter _DO of the orifice 143 is smaller than 1/5 of the diameter D _B of the pure water supply line 123, there is a possibility that a sufficient amount of DIW cannot be supplied from the pure water supply line 123 to the confluence section 141. . On the other hand, if the inner diameter D _O of the orifice 143 is larger than 1/2 of the diameter D _B of the pure water supply line 123, there is a possibility that backflow of sulfuric acid cannot be sufficiently suppressed.

However, in Modification 1, by setting the inner diameter D _O of the orifice 143 in the range of 1/5 to 1/2 of the diameter D _B , a sufficient amount of DIW can be supplied to the confluence section 141. , the backflow of sulfuric acid can be sufficiently suppressed. In addition, in the experimental results of Modification 1 shown in FIG. 9, the inner diameter _DO of the orifice 143 is about 1/4 of the diameter D _B.

Further, in the first modification, the orifice 143 is preferably spaced apart from the mixed liquid supply line 160 by a distance greater than or equal to the diameter D of the mixed liquid supply line 160 at the confluence portion 141 . That is, when the distance between the orifice 143 and the mixed liquid supply line 160 is L2, it is preferable that L2≧D×1.

Thereby, in the first modification, it is possible to prevent the orifice 143 and the mixed liquid supply line 160 from being arranged so as to overlap.

Note that the distance L2 between the orifice 143 and the mixed liquid supply line 160 is preferably as short as possible (for example, L2≦D×5). As a result, the length of the sulfuric acid flowing back from the confluence section 141 can be shortened, so that the occurrence of a bumping reaction in the mixing section 140 can be further suppressed.

Furthermore, in Modification 1, the angle between the sulfuric acid supply line 110 and the pure water supply line 123 at the confluence section 141 is not particularly limited. In Modified Example 1, for example, by connecting the pure water supply line 123 downward to the confluence part 141, sulfuric acid having a specific gravity higher than that of DIW is suppressed from flowing back from the confluence part 141 to the deionized water supply line 123. can do.

Therefore, according to the first modification, when the etching process using the mixed liquid M is finished, it is possible to further suppress the bumping reaction from occurring in the mixing part 140.

Furthermore, in the first modification, the diameter D of the mixed liquid supply line 160 is not particularly limited, and can be appropriately set according to the discharge flow rate of the mixed liquid M necessary for etching the wafer W.

Furthermore, in Modification 1, the diameter _DA of the sulfuric acid supply line 110 at the confluence section 141 and the diameter D _B of the pure water supply line 123 at the confluence section 141 are not particularly limited. In the first modification, the diameter D _A and the diameter D _B can be appropriately set according to the discharge flow rates of sulfuric acid and DIW necessary for etching the wafer W.

FIG. 10 is a diagram showing the configuration of a reaction suppression mechanism according to modification 2 of the embodiment. As shown in FIG. 10, a mixing section 140 according to Modification 2 includes a merging section 141 and a gas replacement section 144. The gas replacement section 144 is another example of a reaction suppression mechanism, and is connected near the confluence section 141 in the pure water supply line 123. The operation of the gas replacement section 144 will be explained below.

FIG. 11 is a timing chart showing a specific example of the behavior pattern of each part in the etching process according to Modification 2 of the embodiment. First, the control unit 18 executes the mixed liquid discharge process shown in FIG. 3(a).

Specifically, the control unit 18 starts supplying sulfuric acid from the sulfuric acid supply line 110 to the mixing unit 140 at time T11, and also starts supplying DIW from the pure water supply line 123 to the mixing unit 140.

As a result, the mixed liquid M is generated in the mixing unit 140, so that the control unit 18 can discharge the mixed liquid M through the nozzle 41a (see FIG. 4). Then, the control unit 18 continues the mixed liquid discharge process until a predetermined time T13.

Furthermore, the control unit 18 operates the gas replacement unit 144 (gas replacement unit: ON) from time T12 immediately before the mixed liquid discharge process is completed to time T14 immediately after the mixed liquid discharge process is completed.

As a result, as shown in FIG. 12, the vicinity of the confluence section 141 of the pure water supply line 123 is replaced with gas, so that the backflow of sulfuric acid to the pure water supply line 123 can be inhibited by the gas. FIG. 12 is a diagram for explaining the operation of the reaction suppression mechanism according to Modification 2 of the embodiment.

That is, in the second modification, it is possible to suppress sulfuric acid from flowing back into the pure water supply line 123 when the etching process is finished. Therefore, according to the second modification, when the etching process using the mixed liquid M is finished, it is possible to suppress the bumping reaction from occurring in the mixing part 140.

In this second modification, the gas supplied from the gas replacement unit 144 to the pure water supply line 123 is preferably a gas that has low reactivity with sulfuric acid or DIW, such as nitrogen gas or dry air.

As shown in FIG. 11, the control unit 18 carries out the sulfuric acid discharge process from time T13 when the mixed liquid discharge process ends to time T15 when the bumping reaction subsides. Then, at time T15, the control unit 18 stops the supply of sulfuric acid from the sulfuric acid supply line 110 to the mixing unit 140, and opens the valve 115 (see FIG. 4) to supply the sulfuric acid liquid remaining in the nozzle 41a. Execute cutting process. Thereby, the sulfuric acid discharge process according to Modification 2 is completed.

FIG. 13 is a diagram showing the configuration of a reaction suppression mechanism according to modification 3 of the embodiment. As shown in FIG. 13, a mixing section 140 according to modification 3 includes a merging section 141 and a cooling section 145. The cooling unit 145 is another example of a reaction suppression mechanism, and is installed near the confluence part 141 in the sulfuric acid supply line 110. The operation of the cooling unit 145 will be explained below.

FIG. 14 is a timing chart showing a specific example of the behavior pattern of each part in the etching process according to Modification 3 of the embodiment. First, the control unit 18 executes the mixed liquid discharge process shown in FIG. 3(a).

Specifically, the control unit 18 starts supplying sulfuric acid from the sulfuric acid supply line 110 to the mixing unit 140 at time T21, and also starts supplying DIW from the pure water supply line 123 to the mixing unit 140.

As a result, the mixed liquid M is generated in the mixing unit 140, so that the control unit 18 can discharge the mixed liquid M through the nozzle 41a (see FIG. 4). Then, the control unit 18 continues the mixed liquid discharge process until a predetermined time T23.

Further, the control unit 18 operates the cooling unit 145 (cooling unit: ON) from time T22 immediately before the completion of the mixed liquid discharge process to time T24 immediately before the completion of the sulfuric acid discharge process.

Thereby, as shown in FIG. 14, the temperature of the sulfuric acid supplied to the confluence section 141 is cooled from the predetermined sulfuric acid supply temperature to the bumping temperature to the lower limit cooling temperature. Then, the control unit 18 ends the mixed liquid discharge process after the temperature of the sulfuric acid supplied to the merging unit 141 falls to the lower limit cooling temperature.

Thereby, even if sulfuric acid and DIW react in the confluence section 141, it is possible to suppress the temperature from rising to the bumping temperature during the reaction. Therefore, according to the third modification, it is possible to suppress the bumping reaction from occurring in the mixing section 140 when the etching process using the mixed liquid M is completed.

Note that, as shown in FIG. 14, the control unit 18 performs the sulfuric acid discharge process from time T23 to time T24 when the temperature of sulfuric acid is at or near the lower limit cooling temperature. Then, the control unit 18 stops the supply of sulfuric acid from the sulfuric acid supply line 110 to the mixing unit 140 at time T24, and also stops the operation of the cooling unit 145 (cooling unit: OFF).

Further, at time T24, the control unit 18 opens the valve 115 (see FIG. 4) to perform a process for draining the sulfuric acid remaining in the nozzle 41a. Thereby, the sulfuric acid discharge process according to Modification 3 is completed.

FIG. 15 is a diagram showing the configuration of a reaction suppression mechanism according to modification 4 of the embodiment. As shown in FIG. 15, a mixing section 140 according to modification 4 includes a merging section 141 and a sulfuric acid substitution section 146. The sulfuric acid substitution section 146 is another example of a reaction suppression mechanism, and is connected near the confluence section 141 in the sulfuric acid supply line 110.

The sulfuric acid substitution section 146 supplies sulfuric acid (hereinafter also referred to as low-temperature sulfuric acid) at a lower temperature (for example, room temperature) than the sulfuric acid heated in the sulfuric acid supply section 100 (hereinafter also referred to as high-temperature sulfuric acid) to the confluence section 141 . The high temperature sulfuric acid remaining in the confluence section 141 is replaced with low temperature sulfuric acid. The operation of the sulfuric acid substitution unit 146 will be explained below.

FIG. 16 is a timing chart showing a specific example of the behavior pattern of each part in the etching process according to Modification 4 of the embodiment. First, the control unit 18 executes the mixed liquid discharge process shown in FIG. 3(a).

Specifically, the control unit 18 starts supplying high temperature sulfuric acid from the sulfuric acid supply line 110 to the mixing unit 140 at time T31, and starts supplying DIW from the pure water supply line 123 to the mixing unit 140.

As a result, the mixed liquid M is generated in the mixing unit 140, so that the control unit 18 can discharge the mixed liquid M through the nozzle 41a (see FIG. 4). Then, the control unit 18 continues the mixed liquid discharge process until a predetermined time T32.

Next, at time T32, the control unit 18 stops the supply of high-temperature sulfuric acid from the sulfuric acid supply line 110 to the mixing unit 140, and starts supplying low-temperature sulfuric acid from the sulfuric acid substitution unit 146 to the mixing unit 140 (sulfuric acid substitution Department: ON).

Thereby, since the confluence section 141 is replaced with low-temperature sulfuric acid, even if the low-temperature sulfuric acid and DIW react in the confluence section 141, it is possible to suppress the temperature from rising to the bumping temperature during the reaction. Therefore, according to the fourth modification, when the etching process using the liquid mixture M is completed, it is possible to suppress the bumping reaction from occurring in the mixing part 140.

Note that, as shown in FIG. 16, the control unit 18 stops supplying DIW from the pure water supply line 123 to the mixing unit 140 at time T33 when the confluence unit 141 has been sufficiently replaced with low-temperature sulfuric acid.

Then, the control unit 18 stops the supply of low-temperature sulfuric acid from the sulfuric acid substitution unit 146 to the mixing unit 140 at a predetermined time T34 (sulfuric acid substitution unit: OFF), and opens the valve 115 (see FIG. 4). , a process for draining the sulfuric acid remaining in the nozzle 41a is performed. Thereby, the sulfuric acid discharge process according to Modification 4 is completed.

FIG. 17 is a diagram showing the configuration of a reaction suppression mechanism according to modification 5 of the embodiment. As shown in FIG. 17, in the mixing section 140 of Modification 5, DIW flows downward with respect to the merging section 141.

In this modification 5, the sulfuric acid flowing upward with respect to the confluence part 141 and the DIW flowing downward with respect to the confluence part 141 join together in the confluence part 141, so that a mixed liquid M is generated in the mixing part 140. .

In this modification 5, since the pure water supply line 123 is provided at a higher position than the merging part 141 near the merging part 141, sulfuric acid having a higher specific gravity than DIW flows back from the merging part 141 to the pure water supply line 123. can be restrained from doing so.

Therefore, according to the fifth modification, it is possible to further suppress the bumping reaction from occurring in the mixing section 140 when the etching process using the mixed liquid M is completed.

In addition, in the example of FIG. 17, an example was shown in which DIW flowing downward into the merging part 141 merges with sulfuric acid flowing upward into the merging part 141, but the direction of the sulfuric acid with which the DIW flowing downward joins is It's not limited to upwards.

For example, as shown in FIG. 18, sulfuric acid flowing approximately horizontally with respect to the merging portion 141 and DIW flowing downward with respect to the merging portion 141 merge at the merging portion 141, so that the mixed liquid M may be generated. FIG. 18 is a diagram showing the configuration of a reaction suppression mechanism according to modification 6 of the embodiment.

Also in this modification 6, since the pure water supply line 123 is provided at a higher position than the merging part 141 near the merging part 141, sulfuric acid having a higher specific gravity than DIW flows back from the merging part 141 to the pure water supply line 123. can be restrained from doing so.

Therefore, according to the sixth modification, it is possible to further suppress the bumping reaction from occurring in the mixing section 140 when the etching process using the mixed liquid M is completed.

Note that in each of the embodiments described so far, pure water (DIW) has been shown as the liquid that forms the mixed liquid M together with sulfuric acid, but the liquid that forms the mixed liquid M together with sulfuric acid is not limited to pure water.

For example, in each embodiment, a hydrogen peroxide solution may be used as the liquid that constitutes the mixed liquid M together with sulfuric acid. That is, in the embodiment, the mixed liquid M may be composed of sulfuric acid and aqueous hydrogen peroxide (moisture + hydrogen peroxide), or the mixed liquid M may be composed of sulfuric acid, aqueous hydrogen peroxide, and various additives. Good too.

Further, in each embodiment, functional water (for example, ozone water or hydrogen water) may be used as the liquid that constitutes the mixed liquid M together with sulfuric acid. That is, in the embodiment, the mixed liquid M may be composed of sulfuric acid and ozone water (moisture + ozone), the mixed liquid M may be composed of sulfuric acid and hydrogen water (moisture + hydrogen), or the mixed liquid M may be composed of sulfuric acid and ozone water (moisture + hydrogen). The mixed liquid M may be composed of functional water and various additives.

In this way, when substrate processing is performed using the mixed liquid M in which various liquids containing water are mixed with sulfuric acid, the temperature of the mixed liquid M may rise due to the reaction between the sulfuric acid and the water when the mixed liquid M is generated. Therefore, there is a possibility that the mixed liquid M will bump in the mixing section 140 when the etching process is finished.

However, in each embodiment, since a reaction suppression mechanism is provided in the mixing unit 140 that mixes various liquids containing water with sulfuric acid, bumping of the mixed liquid M in the mixing unit 140 is suppressed when the etching process is finished. can do.

The substrate processing apparatus (substrate processing system 1) according to the embodiment includes a temperature raising section (heater 107), a mixing section 140, and a discharge section (nozzle 41a). The temperature raising section (heater 107) raises the temperature of sulfuric acid. The mixing unit 140 mixes heated sulfuric acid and a liquid containing water to generate a mixed liquid M. The discharge unit (nozzle 41a) discharges the mixed liquid M onto the substrate (wafer W) within the substrate processing unit 30. The mixing section 140 includes a confluence section 141 where a sulfuric acid supply line 110 through which heated sulfuric acid flows and a liquid supply line (pure water supply line 123) through which a liquid (DIW) flows, and a confluence section 141 where a It has a reaction suppression mechanism that suppresses the reaction between sulfuric acid and liquid (DIW). Thereby, when the etching process using the liquid mixture M is completed, it is possible to suppress the occurrence of a bumping reaction in the mixing part 140.

Further, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the reaction suppression mechanism is constituted by a U-shaped pipe buffer section 142 provided in the liquid supply line (pure water supply line 123). Thereby, when the etching process using the liquid mixture M is completed, it is possible to suppress the occurrence of a bumping reaction in the mixing part 140.

Further, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the top of the pipe buffer section 142 is provided at a higher position than the merging section 141. Thereby, when the etching process using the liquid mixture M is completed, it is possible to further suppress the occurrence of a bumping reaction in the mixing part 140.

Further, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the top of the piping buffer section 142 is located at a distance greater than or equal to the diameter D _B of the liquid supply line (pure water supply line 123) in the confluence section 141. It is also placed in a high position. Thereby, it is possible to further suppress sulfuric acid from flowing back to the top of the pipe buffer section 142.

Further, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the piping buffer section 142 is configured to connect the mixed liquid supply line 160, which supplies the mixed liquid M from the confluence section 141 to the discharge section, with respect to the mixed liquid M at the confluence section 141. They are spaced apart by a diameter D or more of the liquid supply line 160. Thereby, it is possible to prevent the piping buffer section 142 and the mixed liquid supply line 160 from being arranged so as to overlap each other.

Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the reaction suppression mechanism is configured with an orifice 143 provided in the liquid supply line (pure water supply line 123). Thereby, when the etching process using the liquid mixture M is completed, it is possible to suppress the occurrence of a bumping reaction in the mixing part 140.

Further, in the substrate processing apparatus (substrate processing system ₁ ) according to the embodiment, the inner diameter D _O of the orifice 143 is 1/5 to 1/ It is 2. Thereby, a sufficient amount of DIW can be supplied to the confluence section 141, and backflow of sulfuric acid can be sufficiently suppressed.

Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the reaction suppression mechanism includes a gas replacement unit 144 that replaces the liquid supply line (pure water supply line 123) with gas. Thereby, when the etching process using the liquid mixture M is completed, it is possible to suppress the occurrence of a bumping reaction in the mixing part 140.

Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the reaction suppression mechanism includes a cooling unit 145 that cools the heated sulfuric acid in the sulfuric acid supply line 110. Thereby, when the etching process using the liquid mixture M is completed, it is possible to suppress the occurrence of a bumping reaction in the mixing part 140.

Further, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the reaction suppression mechanism includes a sulfuric acid substitution section 146 that substitutes the confluence section 141 with sulfuric acid having a lower temperature than the heated sulfuric acid. Thereby, when the etching process using the liquid mixture M is completed, it is possible to suppress the occurrence of a bumping reaction in the mixing part 140.

Further, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the liquid (DIW) flows downward with respect to the merging portion 141. Thereby, when the etching process using the liquid mixture M is completed, it is possible to suppress the occurrence of a bumping reaction in the mixing part 140.

Further, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the liquid is pure water (DIW). Thereby, of the tungsten and titanium nitride contained in the film formed on the surface of the wafer W, titanium nitride can be etched with high selectivity.

Further, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the liquid includes hydrogen peroxide solution. Thereby, the wafer W can be efficiently etched.

Further, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the liquid includes functional water. Thereby, the wafer W can be efficiently etched.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various changes can be made without departing from the spirit thereof. For example, in the above embodiment, this technique can be applied not only to the process of etching one of the plurality of films formed on the substrate, but also to the process of cleaning the substrate.

For example, when a tungsten film is formed on a substrate, it can be applied to remove residues after dry etching or CMP (Chemical-Mechanical Polishing) processing.

Further, in the above embodiment, an example was shown in which the wafer W is etched with the mixed liquid M and then rinsed, but the treatment after etching is not limited to rinsing, and any type of treatment may be performed.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. Indeed, the embodiments described above may be implemented in various forms. Moreover, the above-described embodiments may be omitted, replaced, or modified in various forms without departing from the scope and spirit of the appended claims.

W Wafer 1 Substrate processing system (an example of substrate processing equipment)
16 processing unit 18 control section 30 substrate processing section 41a nozzle (an example of a discharge section)
60 Mixed liquid supply section 100 Sulfuric acid supply section 107 Heater (an example of a temperature increasing section)
110 Sulfuric acid supply line 120 Pure water supply section 123 Pure water supply line (an example of liquid supply line)
140 Mixing part 141 Merging part 142 Piping buffer part (an example of a reaction suppression mechanism)
143 Orifice (an example of reaction suppression mechanism)
144 Gas replacement part (an example of reaction suppression mechanism)
145 Cooling section (an example of reaction suppression mechanism)
146 Sulfuric acid substitution part (an example of reaction inhibition mechanism)

Claims (13)

a heating section that raises the temperature of sulfuric acid;
a mixing section that mixes heated sulfuric acid and a liquid containing water to generate a mixed liquid;
a discharge unit that discharges the mixed liquid onto the substrate in the substrate processing unit;
Equipped with
The mixing section is
a confluence section where a sulfuric acid supply line through which heated sulfuric acid flows and a liquid supply line through which the liquid flows;
comprising a reaction suppression mechanism that suppresses a reaction between the heated sulfuric acid and the liquid in the confluence section,
The reaction suppression mechanism includes a U-shaped piping buffer section provided in the liquid supply line.
Substrate processing equipment. The substrate processing apparatus according to claim 1 , wherein the top of the pipe buffer section is provided at a higher position than the merging section. The substrate processing apparatus according to claim 2 , wherein the top of the pipe buffer section is provided at a position higher than the merging section by a diameter of the liquid supply line at the merging section. The piping buffer section is spaced apart from a mixed liquid supply line that supplies the mixed liquid from the merging section to the discharge section by a diameter greater than or equal to the diameter of the mixed liquid supply line at the merging section . substrate processing equipment. a heating section that raises the temperature of sulfuric acid;
a mixing section that mixes heated sulfuric acid and a liquid containing water to generate a mixed liquid;
a discharge unit that discharges the mixed liquid onto the substrate in the substrate processing unit;
Equipped with
The mixing section is
a confluence section where a sulfuric acid supply line through which heated sulfuric acid flows and a liquid supply line through which the liquid flows;
comprising a reaction suppression mechanism that suppresses a reaction between the heated sulfuric acid and the liquid in the confluence section,
The reaction suppression mechanism is comprised of a sulfuric acid substitution unit that replaces the merging unit with sulfuric acid having a lower temperature than the heated sulfuric acid.
Substrate processing equipment. 6. The substrate processing apparatus according to claim 1, wherein the reaction suppression mechanism includes an orifice provided in the liquid supply line. The substrate processing apparatus according to claim 6, wherein the inner diameter of the orifice is 1/5 to 1/2 of the diameter of the liquid supply line in the merging section. The substrate processing apparatus according to any one of claims 1 to 7, wherein the reaction suppression mechanism includes a gas replacement section that replaces the liquid supply line with a gas. 9. The substrate processing apparatus according to claim 1, wherein the reaction suppression mechanism includes a cooling unit that cools the heated sulfuric acid in the sulfuric acid supply line. The substrate processing apparatus according to any one of claims 1 to 9 , wherein the liquid flows downward with respect to the merging section. The substrate processing apparatus according to claim 1 , wherein the liquid is pure water. The substrate processing apparatus according to any one of claims 1 to 10 , wherein the liquid includes a hydrogen peroxide solution. The substrate processing apparatus according to any one of claims 1 to 10 , wherein the liquid includes functional water.

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